body{
    background:url(../images/back_image.jpg) center center;
    background-repeat: no-repeat;
    background-size: cover;
    background-attachment: fixed;
    margin: 0%;
    padding: 0%;
    position: relative;
    color: #ffffff;
    font-family: sans-serif;
}
.header{
    margin-top: 8px;
    width: 100%;
    height: 6%;
    background-color: rgba(0, 60,123,0.8)
}
.header ul{
    margin: 0%;
}
.header li{
    margin-top: 8px;
    list-style: none;
    font-size: 20px;
    float: left;
}
.nav:hover{
    color:orange;
    border-bottom: 0px solid white;
    padding-bottom: 8px;
    transition: 0.3s;
}
.nav{
    float: right;
    font-size: 8px;
    margin-top: 25px;
}
.nav_left{
    float: left;
    font-size: 20px;
    margin-left: 4%;
    margin-right: 4%;
    margin-top: 10px;
}

.nav_right{
    float: right;
}

.nav_title{
    float: left;
    font-size: 20px;
    margin-right: 30px;
    margin-top: 10px;
}
a{
    text-decoration: none;
    padding: 0px;
    color: white;
    font-size: 20px;
}
a:hover{
    color: orange;
}

.line{
    width: 100%;
    height: 1px;
    background-color: rgba(0, 0,0,0.3);
    margin-top: 5px;
    margin-bottom: 5px;
}
.list-group-item.active{
}
.list-group-item{
    /*height: 50px;*/
    padding:7px 5px 5px 10px;
    color:black;
}
.detail span{
    font-size: 12px;
    color: #6c757d;
    margin-right: 10%;
}
.change{
    display: none;
    position: absolute;
    bottom: 10px;
    right: 10px;
    font-size: 0.7em;
    font-weight: bold;
    color: black;
}
.content dd{
    font-size: 12px;
    font-weight: bold;
    color: #666;
}
.bck{
    position: absolute;
    left: 0;
    top: 0;
    z-index: 99999;
    width: 100%;
    height: 50px;
    margin:-1px
}
.bck:hover{
    background-color: rgba(0, 0, 0, 0.8);
}
.nav-item{
    margin-left: 100px;
}
.user{
    position: absolute;
    right: 2%;
    bottom: 20px;
}
mark{
    background-color:yellow;
}